1. Field of the Invention
The present invention relates to a multi-block copolymer, a pressure-sensitive adhesive composition, a method of preparing a multi-block copolymer, a pressure-sensitive adhesive polarizing plate, and a liquid crystal display (LCD) device.
2. Discussion of Art
Recently, a variety of copolymer materials have been required, but a single polymer to meet such a requirement is difficult. Accordingly, attention to polymer alloys, that is, block copolymers, to obtain desired physical properties by mixing different polymers is increasing.
Methods of preparing a block copolymer, initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP), and activator regenerated by electron transfer atom transfer radical polymerization (ARGET-ATRP) are known.
As a use of the block copolymer, a pressure-sensitive adhesive field may be considered.
Particularly, to apply the block copolymer as an optical member such as a polarizing plate, a high molecular weight is required to ensure durability.
In Korean Unexamined Patent Publication Nos. 2010-0011179 and 2009-0072861, pressure-sensitive adhesive compositions to achieve such physical properties are disclosed.
However, the block copolymer is difficult to be synthesized at a high molecular weight due to its characteristic.